Question: question 3 3 marks a ray of light is incident...
Question 3 (3 marks)
A ray of light is incident on an air/glass interface at an angle of 30o to the normal. Calculate the angle of refraction of the ray in the slab.
Question 4 (3 marks)
Calculate the critical angle at which a ray of light must hit a glass/air interface to be totally internally reflected.
Question 6 (1 mark)
Explain why a mechanical wave needs a medium to transfer energy
Question 9 (3 marks)
To deaden pain in minor operations, a liquid that vaporises easily is sometimes sprayed onto the skin. Using thermodynamic principles, explain how this liquid cools the skin and when the effect ends.
Question 10 (4 marks)
A current-carrying wire runs horizontally across a table. The conventional current direction, I, is running from left to right. The wire produces a magnetic field of 2.8 x 10-6 T measured 15.4 cm from the wire A. What current must the wire be carrying to produce this field? 3 Marks
B. Draw a diagram showing the direction of the magnetic field around the wire. 1 Mark